Panel Uncertain Of Radon's Effects

Although radon gas has only recently become an issue of public concern in the Lehigh Valley, it isliterally older than the hills and much farther reaching.

The rock formations which emit the gas have existed, not just in the Reading Prong, but nationwide, for more than a billion years, according to a geologist speaking yesterday at Lehigh University. But despite the age of the gas, experts at Lehigh maintained that the extent to which it affects health and a sure-fire way of eliminating it from homes are not yet known.

Panelists agreed that while radon presents a problem, that problem is not limited to one area and the gas is not normally present at severe levels. They felt the public should be better informed about the gas and explained the geographical conditions which create it as well as its physical qualities, health effects and the potential solutions for its removal from homes.

The panel was part of a seminar, "Residential Radon - A Lehigh Valley Dilemma," sponsored by Lehigh's Office of Continuing Education and the American Lung Association of the Lehigh Valley.

Radon is a radioactive gas produced naturally in the ground by the normal decay of uranium and radium. The gas is believed to contribute to the risk of lung cancer.

The presence of vast deposits of this gas along the Reading Prong, an area extending northeast from Reading through southeastern New York, was well publicized. But Dr. Paul B. Myers Jr., a professor of geology at Lehigh, said that this area "is no different from many other areas in North America and probably the world." Its notoriety stems from the fact that "this is where we looked first."

Myers said the Prong is a topographic feature made of various rock formations containing uranium-bearing minerals like allanite, zircon, monazite and thorianite, which are "about a billion years old" and once were the major rock formations of the continent.

In the Prong area, they were "juxtaposed" in a land shift and sit on top of newer rocks, closer to the surface. Myers said that the decay of the uranium in the minerals takes place in a crystal lattice and that the resulting gas, radon, gets trapped and must escape. It does this through cracks in the earth's surface as well as through the soil.

"The rocks of the Reading Prong are really busted up," he said. "There are all kinds of access routes for its escape."

Myers said that the levels of radon in the Prong vary from place to place. He said that in the Lehigh Valley the problem is less pronounced than in other areas, but that even though the area has shown "some very high radon levels and it is something to be concerned about, it's not a really high-grade uranium ore." He said the problem is much less serious here than some areas of Colorado, where uranium mining has taken place.

Dr. Max Weiss, manager of the radiation protection department at AT&T's Bell Laboratories, explained that radon's decay series ends up as lead 210, but between the stages it becomes such forms as radium, lead, bismuth and polonium.

These forms emit alpha particles, which have a positive charge and attach themselves to other particles such as dust. Although alpha particles cannot penetrate more than a short range, they still contain much energy. Thus, when one passes into the lungs, "It deposits all that radioactive energy within a very short range and can be very dangerous," he said.

Dr. Terry Pundiak of Easton Hospital said that although alpha rays cannot pass through material thicker than a sheet of paper, "The lining of the lungs is thinner than a sheet of paper." He said that radiation, such as that caused from inhaling radon decay forms or smoking, has been estimated to cause about 2.5 percent of all cancers.

In presenting material about the health effects of radon, Pundiak noted that the actual risk is uncertain because of the types of studies conducted and the statistics available. Though radon has been suspected of contributing to lung cancer since 1930, studies of lung cancer in miners did not fit the anticipated averages, since the studies estimated rather than measured the radon levels and did not take into account the number of miners who smoked.

"There are no studies completely proving the effect of radon," he said.

In fact, Pennsylvania counties in the heart of the Reading Prong have an average of lung cancer deaths consistent with the national average. Philadelphia and Allegheny counties had the highest cancer deaths, according to Pundiak, but he attributed the rate to the large numbers of smokers in metropolitan areas.

"Smoking causes so much cancer that it clouds the statistics," Pundiak said.

Two sets of statistics that he presented, however, indicated that at a level five times higher than what is recommended by the state's department of environmental resources, radon would present a risk increase of between 20 and 60 percent - about 35 percent for contracting lung cancer.